Boeing [BA] said Wednesday it finalized a $2.8 billion contract with the National Aeronautics and Space Administration (NASA) for the core stage of the Space Launch System (SLS).

NASA and ATK engineers complete structural loads testing on the Space Launch System (SLS) booster forward skirt at ATK’s facility in Promontory, Utah. Photo: ATK.
NASA and ATK engineers complete structural loads testing on the Space Launch System (SLS) booster forward skirt at ATK’s facility in Promontory, Utah. Photo: ATK.

This latest contract combines the two Ares contracts previously awarded for the core and upper stages, for which Boeing had been chosen as the prime contractor during a competitive selection in 2007. The new combined SLS contract is also modified to meet the NASA Authorization Act of 2010. It will now extend the design, development, test and evaluation portion of the SLS contract from 2014 through 2021 in accordance with NASA’s plans for human space exploration, according to a Boeing spokesperson.

The company will also study the SLS Exploration Upper Stage to determine future payload and range capabilities, Boeing said in a statement.

SLS–the most powerful heavy launch system to date–will replace the retired space shuttle program. It is being developed in tandem with the Orion spacecraft to provide the next generation of human space exploration.

Boeing and NASA recently completed the Critical Design Review (CDR) on the core stage, which Boeing said is the last major review before full production can begin. SLS is set to reach initial testing by 2017. The first tests will launch a 77-ton capacity with future capabilities reaching 143-ton lift.